Issue #66: Add more utility methods to URLUtil.

* Remove/Extract token.

* Ensure valid query string key-value pairs.

* Remove/Extract query string.
Issue #66: Preserve query string in Service Browser.
Issue #66: Store token from ConfigLayer URL internally.
Issue #66: Remove non-Builder URL tokens for metadata requests.
Issue #66: Remove unused imports.
Issue #66: Strip invalid key-value pairs from URL query string when making requests on user input.
Issue #66: Remove query strings when evaluating URLs internally.
Issue #66: Fix token helper functions not working with non-alphanumeric characters.
Merge branch '#66/preserve-url-query-strings' into develop